Have have a Gigaset S685 on open VFX for over a year and it has worked well. In the last week I have noticed that there are a few phone numbers (local) that I cannot call. I can hear a max of one ring before the connection is dropped. The called party says phone rings like normal, when they answer no one is there. One of the numbers with the issue I would have rung many times in the last year without issue.
I can PM my details, number called and time of call if this will help. I will be able to do a packet trace tomorrow if this is required.
I cannot think of anything that has changed at this end.